UN Nuclear Chief Heading to Iran

The head of the United Nations nuclear watchdog will visit Iran Sunday in an apparent push for progress in a long-running investigation into suspicions the country has worked to develop nuclear weapons.

Yukiya Amano's trip comes ahead of an August 25 deadline for Iran to answer allegations about its disputed nuclear program.

The International Atomic Energy Agency announced the trip on Friday, saying it is "part of the efforts to advance dialogue and cooperation" with Iran.

The so-called P5+1 -- which includes the United States, Britain, China, France, Germany and Russia -- has been negotiating with Iran on a comprehensive nuclear deal. In mid-July, the parties extended the deadline for an agreement until November 24.

A temporary agreement reached by the two sides last November eased sanctions against Iran, which curbed its uranium enrichment program in exchange.

Iran has rejected accusations it is trying to build nuclear weapons, saying its nuclear program is solely for peaceful purposes.